Hair drying apparatus



Dec. 11, 1956 J. H. o'c NNoR 2,773,313

HAIR DRYING APPARATUS Filed June 19, 1950 'T Sheets-Sheet 1 3 370 N/Gl/T 75 DRY 5 3 7 OFF IN VEN TOR. JbJEPA /S! 060mm? Dec. 11,1956 J. H. O'CONNOR 2,773,313

HAIR DRYING APPARATUS Filed June 19, 1950 '7 Sheets-Sheet 2 II\{VEN TOR. fisEI-W /7. 0 CON/MOE ATTORNEY Dec. 11, 1956 J. H. O'CONNOR HAIR DRYING APPARATUS '7 Sheets-Sheet 3 Filed June 19, 1950 30 7 INKENTOR.

Js P/Y 0 (by/V0 BY W\ 4770 Mey Dec. 11, 1956 .1. H. OCONNOR HAIR DRYING APPARATUS 7 Sheets-Sheet 4 Filed June 19,- 1950 IIYVENTOR. Jose/ b. 0 COM V01? W Z A77?) NEY Dec. 11, 1956 J. H. OCONNOR 2,773,313

HAIR DRYING APPARATUS Filed June 19, 1950 (Sheets-Sheet 5 I NlfEN TOR. @551 b. 0 Com/v02 Dec. 11, 1956 J. H. O'CONNOR HAIR DRYING APPARATUS 7 Sheets-Sheet 6 Filed June 19, 1950 1956 J. H. O'CONNOR 2,773,313

HAIR DRYING APPARATUS Filed June 19, 1950 '7 Sheets-Sheet '7 IN V EN TOR. Jsszw/ b. 0 Co/v/vo/Q 850 y 32 ATTORNE United States Patent 2 ,773,313 HAIR DRYING APPARATUS Joseph H; OConhor, Detroit, Mich assignor, by direct and mesnetassignments, to Harold J. Silver and Evelyn B. Silver, Dallas, Tex.

Application June is, 1950', Serial No. 168,909 10 Claims. c1. s t -4s This invention relates to hair drying apparatus and in particular to improvements inhair dryers of the type employed in beauty salons and the like.

The primary object of the invention is to provide an improved and highly efiicient hair dryer which drys hair comfortably and rapidly, employing low velocity recirculated desiccant dehumidified air in its hair drying cycle of operation including a comfort heater to increase, at the option of the user, ,the' temperature of d'ehuinidified air Supplied to and circulated through the drying helmet, the hair dryer further incorporating a manually initiated and thermal responsive shut-off desiccant regeneration cycle of operation, and a manually regulated ambient air bleed to dehumidified air in the hair drying cycle of operation including a safety interlock preventing ambient air bleed to the thermal responsive desiccant regeneration cycle shut-off means. I

Other objects of the invention will becomeapparent by reference to the following detailed description taken in connection with the accompanying drawings, in which:

Fig. i is a top plan view of a hair dryer embodying the invention.

Fig. 2 is a front elevational view.

Fig. 3 is a fragmentarysectional view taken on the line 33 of Fig. 1 showing the ambient air bleed vent sliding door in its closed position with the regeneration safety interlock switch in its closed position.

Fig. 4 is a sectional view similar to Fig. 3 except that the ambient air bleed vent sliding door is in a partially open position with the regeneration safety interlock switch in its open position.

Fig. 5 is a longitudinal sectional view taken on the line 5-5 of Fig. 8. r r

Fig. 6 is a vertical sectional view taken on the line 6 6 of Fig. 5.

Fig. 7 is a horizontal sectional view taken on the line 7-7 of Fig. 5 looking in the direction indicated by the arrows.

Fig. 8 is a horizontal sectional view taken on the line 3-8 of Fig. 5 looking in the direction indicated by the arrows.

Fig. 9 is a general wiring diagram showing the electrical controls and circuits preferably employed. I

Fig. 10 is a more or less diagrammatic view showing the recirculation, of air through the hair dryer during the hair drying cycle of operation.

Fig. 11 is a more or less diagrammatic view showing the passage of air through the hair dryer during the reactivation cycle of operation. v

Figs. 12, 13, 14 and 15 show the position of the manual and electrical controls and air flow control bafile when the hair dryer selector control knob is turned to its oh? position. 7 4

Figs. 16, 17, 18 and 19 show the position of the manual and electrical controls and, air ,flow control, bafile when the hairdryer selector "control knob is turned to its dry or hair drying cycle position.

Figs. 20, 21, 22 and 23 show the position of the manual 2,773,313 Patented Dec. 11, 1956 and electrical controls and air flow control bathe when the hair dryer selector control knob is turned to its night or regeneration cycle position. v v V A, Referring now to the drawings wherein like numerals refer to like and corresponding parts throughout the 'sev eral views, the particular desiccant dehumidified recited lated air type hair dryer disclosed for the purpose of illus= tratingthe invention comprises, in general, a housing 25 into which the air circulating and dehumidifying elements of the hair dryer are positioned and a helmet 26 supported in vertically slidable relationship from the said housing 25, the said helmet 26 being placed over the head of a person during the hair drying ygle pf op'eration of the hair dryer andinto which dehiiinidified air fromthe hair dryer is supplied by a blower 27 and from which helmet 2'6 moisture laden air is drawn and circulated by the said blower 27 for dehumidification through a desiccant 2 8 such as silica gel disposed in areticulated desiccant basket29. During the regeneration cycle of operation, ambient air is drawn from the helmet 26 through the desiccant 28 in the desiccant basket, by the blower 27 for regeneration of the desiccant 28, and moisture laden air from the blower 27 is discharged to ambient air at the bottom of the hair dryer. A comfort heater provided to heat dehumidified air supplied into the helmet 25 at the option oftheuser of the hair dryer during the hair drying cycle of operation to prevent ateeling of coldness of the scalpdtie to evaporation of moisture from the hair being dried. A lso ilnder conditions erasin the hair dryerin an extremely warm roorri or during hot summer months, an ambient air bleed 31 is provided to mix a' small portion of ambient air into the air recir'culation system after moisture laden air has been dehumidified wherebyto lower thetemperature of the recirculating air after dehumidification which mayotherwise raise to an uncomfortable temperature due to latent heat of adsorption of moisture therefrom by the desiccant 28. reactivation heater32 providedto heat ambient air prior" to being drawn through the desiccant zs diirir'lgtthe regeneration cycle of operation of the hair dryerto make more effective and shorten the time required to regenerate thej' desiccant 28. The foregoing is accomplished with new and improved extremely eflective and efiicient structure and arrangement o'felements together with an improved and novel combination of mechanical, electrical and thermal controls, all as hereinafter more fully described in detail. v p

Th housing 25 preferably comprises a top casting 33, a base casting 35 having a plurality of casters 36 thereon and an outer shell 37. In the housing 25 is a casting forming a horizontal partition 38 to the: bottom of which is secured a sub-casting 39 forming in conjunction with the said horizontal partition 38 the blower impeller housing 40 and the blower discharge duct 41 of the blower 27, the said horizontal partition 38 having the blower intake 42 and the blower discharge port 43 formed there in. ,A collar 431 is provided around the blower, discharge port 43 to accommodat a vertically disposed dehumidified air supply tube 44 extending upwardly to a point near the top t ng 3 t a i "[eles coped over the said dehumidified air supply tube and invertically slidable relationship thereto is a dehumidified air supply conduit 45.,diSPOsed within a nio'isture laden air return conduit 46 which is telesctojped. in vertically slidahle relationship through an aperture 47 in the top casting 33. On the tops of the air supply tube {l4 and the moisture laden air return conduit 46 is fixed a helmet supporting neck 48 into which is formed a dehumidified air supply-duct 49 and a moisture laden air return duct '50.. The lower end of the air ret'nrn' coiiduit 46 opens into the moisture laden air chamber 250 ofthe housing 25 at 460.

The helmet 26 has an outer shell 51 and an inner shell 52 with a dehumidified air supply distribution chamber 53 therebetween. A dehumidified air supply port 54 in the rear of the outer shell 51 of the helmet 26 communie'ates with the dehumidified air supply duct 49 in the helmet supporting neck 48. A moisture laden air return port 55 extends through the helmet 26 at the top thereof and communicates with the moisture laden air return duct 50 in the helmet supporting neck 48.

In the housing 25 is partitioned off by a vertically disposed circular partition 56 a cylindrical dehumidified air chamber 57, the said circular partition 56 being disposed around the blower intake 42 and extending upwardly from the horizontal partition 38 to an elevation somewhat short of the underside of the top casting 33. From the top of the said circular partition 56 and suspended into the cylindrical air dehumidifying chamber 57 is the desiccant basket 29. The said desiccant basket 29 is annular in form having spaced inner and outer cylindrical reticulated walls 58 and 59 an annular solid top 60 and a circular solid bottom 61. The annular solid top 60 of the desiccant basket 29 is coextensive of the inner and outer cylindrical reticulated walls 58 and 59 thereof and the circular partition 56. The solid bottom 61 of the said desiccant basket 29 is disposed in spaced relationship above the horizontal partition 38 of the housing 25. This construction causes all moistur laden air drawn by the blower 27 from the moisture laden air return conduit 46 at its opening 469 within the housing 25 to pass to the inside of the top of the housing 25 above the annular solid top 60 of the desiccant basket 29, through the inner chamber 290 of the desiccant basket 29, and through the desiccant 28 disposed in the desiccant basket 29 where the moisture laden air drops its moisture and passes as substantially dry air into the cylindrical dehumidified air chamber 57 from whence it is drawn into the blower intake 42 by the impeller 270 of the blower 27.

During the hair drying cycle of operation, the impeller 270 of th blower 27 which is driven by an electric motor 62 preferably suspended from the sub-casting 39 of the horizontal partition 38 draws moisture laden air from the helmet 26 through the desiccant basket 29 where the moisture in the moisture laden air is deposited on the desiccant 28 and then returns the relatively dry or dehumidified air to the helmet 26 through the blower discharge duct 41, the blower discharge port 43, the dehumidified air supply tube 44, and the dehumidified air supply duct 49 from whence the dehumidified air is circulated through the hair of a person using the hair dryer from a plurality of nozzles or apertures 63 formed in the inner shell 52 of the said helmet 26. The relatively dry or dehumidified v air becomes moisture laden as it passes through the head cavity 260 of the helmet 26 by picking up moisture from the hair of the person using the hair dryer, and the moisture laden air is dehumidified and recirculated as above described. By referring to Fig. 10, the recirculation of air through the hair dryer during the hair drying cycl of operation will be observed, the dotted lines incorporating arrows showing the path of moisture laden air and the full lines incorporating arrows showing the path of dehumidified air.

A comfort heater in the form of a resistance heating element 30 preferably located in the dehumidified air supply tube 44 under the control of a comfort heater switch 65 conveniently located on the helmet 26 warms dry air as it is forced from the blower 27 to the helmet 26 whereby to provid the user of the dryer comfortably warm air to offset any feeling of coolness on the users scalp caused by evaporation of moisture in the hair adjacent the scalp. A reading lamp switch 66 also located on the helmet 26 controls a reading lamp 67 which may be provided for the convenience and pleasure of the user of the hair dryer.

During the drying cycle of operation of the hair dryer the recirculated dehumidified air to the helmet 26 may become too warm for comfort due to the latent heat of.- adsorption created when moisture laden air deposits its moisture on the desiccant 28 when passing through the desiccant basket 29. To compensate for the foregoing, the ambient air bleed 31 is provided which comprises a. manually operated ambient air bleed sliding door 68- which normally closes an ambient air passage 69 communicating between ambient air and the cylindrical dehumidified air chamber 57. When the said manually operated ambient air bleed sliding door 68 is opened either partially or fully, ambient air is drawn into the cylindrical dehumidified air chamber 57 and mixes with dehumidified air from the desiccant basket 29. The extent to which the ambient air bleed is permitted is governed by the extent to which the manually operated ambient air bleed sliding door 68 is opened.

When the hair dryer is not in use, preferably at night when a beauty salon employing hair dryers embodying the invention is closed, the desiccant 28 in the desiccant basket 29 is reactivated, that is, the moisture adsorbed thereby is removed therefrom. This reactivation of the desiccant 28 is accomplished by drawing ambient air at an elevated temperature through the desiccant 28 in the desiccant basket 29. The ambient air is heated prior to being drawn through the desiccant 28 by means of the reactivation heater 32 preferably disposed in the inner chamber 299 of the desiccant basket 29.

To reactivate the hair dryer, the reactivation cycle of operation is initiated whereupon ambient air is drawn by the blower 27 into the housing 25 through the moisture laden air return port 55 at 'the helmet 2 5, through the moisture laden air return duct 50 of the helmet supporting neck 48, through the moisture laden air return conduit 46 into the housing 25 at the open' end 466 of the said moisture laden air return conduit 46 and through the desiccant 28 in the desiccant basket 29 Where the said ambient air picks up moisture from the said desiccant 2.8 and passes as humid reactivation air to and through the cylindrical dehumidified air chamber 57 and then is discharged by the said blower 27 through the blower discharge duct 41 and the humid reactivation air discharge outlets 71 and '72 in the bottom of the blower discharge duct 41 and the base casting 35 respectively. A hinged baflle 73 hinged by a hinge pin 730 is disposed in the blower discharge duct 41 and closes oft" the passage of humid reactivation air from the blower discharge duct 41 to the blower discharge port 43 during the reactivation cycle of operation of the hair dryer, the said hinged bafiie 73 also closing off the passage of dehumidified air to the humid reactivation air discharge outlets 71 and 7-2 during the hair drying cycle of operation of the hair dryer. By referring to Fig. ll, the circulation of ambient and humid reactivation air through the hair dryer during the reactivation cycle of operation of the hair dryer will be observed, the full lines incorporating arrows showing the path of ambient air and the dotted lines incorporating arrows showing the path of humid reactivation air.

Although not described in detail, the several elements of the hair dryer are secured into an integral operating struc* ture by such suitable means as bolts, machine screws, rivets and sheet metal screws employing gaskets where required to make both fixed and sliding joints air tight, ready removal of the outer shell 3'7 of the housing 25 of the hair dryer being provided by the use of a plurality of ornamental exteriorly secured clamps 370 along the front seam of the said outer shell 37.

Of importance are the manual and automatic mechanical, thermal and electrical controls which provide a perfectly balanced selective operation of the hair dryer both in its hair drying and reactivation cycles of operation. Although the illustrative embodiment of the hair dryer herein disclosed is indicated to be coin operated, it is obvious that the coin controlled switch 74 which coin controls the drying cycle of operation may be omitted if desired.

owners The electrical system, including the comfort heater 64 and it-he reading Clamp "67 which are controlled hy the comfort h'ea'ter swit-oh 65 and the reading lamp switch :66 respectively l ocated on the helmet 26, employs the coin controlled switch 7 4 to initiate the drying'cycle of operation. A selector control mechanism which:is selectively operated by a selector control knob 75 including a pointer 7-50 which may be turned to an Oil position, a Dry position for the drying cycle of operationxand a-N-ight position for the reactivation cycle of-operat-ion -all. as indicated on the selector controldial 76. t

The selector COflllOlikIlOb '75is located ont-hetop of the top casting 33 and is fixed to a vertically disposed selector control rod 77 which 'extends downwardly in 'turn'able relationship through the top casting 33, the horizontal partition 38 and the sub-casting 39, below which the said selector control rod 77 is bent atright angles to pro'vide a selector control lever 78 whichengages a suitably formed rod type cam 79 secured to the hinged baffle 73 in the blower discharge duct 41 1w such means as a stud '80, the said cam 79 havinga portion79t) which is contacted by the control lever 78 to close the said hinged battle [3 when the selector control knob 76 is turned to its Otf or to its .Dry or hair drying cycle position and a portion 791 which is contacted by the control. lever 78. to, open the said hinged baifie 41 when the selector control knob 76 is turned to its Night or reactivation cycle position. Thus, one of the functionscf the selector control knob 75 is to close the hinged bafile 41 during the Oil and Dry or hair drying cycle position and open the said hinged baffie 41 during its Night orreactivation cycle position.

Referring now to Fig. 9, the electric controls and circuits employed to operate the hair dryer herein described are shown diagrammatically. Current is supplied to the hair dryer from an alternating current source 8 through a power plug til from which power is supplied to the blower motor 62 during the hair drying cycle of operation of the dryer and during the reactivation cycle of operation, to the comfort heaterfitl and the reading lamp 67 at the option of the user through a manually operated comfort heater switch 65 and reading lamp switch6 6 during the hair drying cycle of operation, and to the reactivation heater 32 during the reactivation cycle of operation, under control of the coin controlled switch 74, a micro-switch 82, a relay 33, a reactivation cycle thermostatic shut' oft switch 84 and a safety ambient air bleed interlock microswit-ch 85, the said micro-switchSZ and relay 33 being operated manually by camsfiZttti and cf'shtl respectively mounted on the selector control rod 77 responsive to selective movement of the selector control knob 75.

Fig. 9 shows the electrical control circuit for the hair dryer in its on position. At this time the current to operate the hair dryer is available through the power plug 81 connected to a suitable source of electric current S. The coin control switch 74 is open. The micro-switch 82 has its contacts 325 and 821 spring loaded closed and its contacts 820 and 322 open thereby passing current to Contact 33 of the relay S3 with respect to which contact 831 thereof is spring loaded open. Contacts 832 and $33 of relay 53 are spring loaded closed and its contacts 832 and 83 are open. The reactivation cycle thermostatic shut-off switch 84 is closed. The ambient air bleed interlock micro-switch 85 which is spring loaded open may be either open or closed, all according" to whether or not the ambient air bleed sliding door 68' is open or closed. The said ambient air bleed interlock micro-switch 85 must be closed by the closed ambient air bleed sliding door 68 or .the regeneration cycle of operation of the dryer will not function. This is to assure proper functioning of the reactivation cycle thermostatic shut-on switch 84. The comfort heater switch 65 and the reading lamp switch 66 may be open as shown or closed.

By referring to Figs. 3 and 4, the air bleed interlock microewncn 85whi'ch has a spring loaded contact plunger 850 which is contacted bythe ambient air bleed sliding 6 door 68 is shown closed in Fig. when "thetambientxair bleed sliding door 63 is closed and .o p'en inrFig. 4 when the ambient air bleed sliding door 68 is partially or fully opened. 7

Referring now to Fig. 12, the selector control "knob 75 is turned so that its pointer 750 points to the 'Off position on the selector control dial 76. Therebel'owon the selector control rod 77 is the relay, cam #8300v which is out of contact with the relay 83. Still farther therebelow on the selector control rod 77 is the micro-switch cam 8209 which is out of contact wit-h the micro-switch 82. The relay cam $300 is shown as an angularly bent rod threaded through and nut anchored to the selector control rod 77 in the desired adjustment. The micro-switch cam 8290 is "shown as a round head stud threaded through and nut anchored to the selector control rod 77 in the desired adjustment.

Figs. 13 and 14 show the position of the selector control lever 14 out of engagement with the contact portions 7% and 79l of the rod type cam 79 secured to the hinged baffle 73 in the blower discharge duct 41 by the stud 80, the said baflle 73 being'shownvin its closed position sealing off the humid reactivation air discharge outlet 71 in the said blower discharge duct 41.

Fig. 15 repeats, in part, that portion of the wiring diagram and electrical controls shown in Fig. 9 as are affected by the operation of the selector con-trol knob 75; the electromechanical controls being shown in the Off position in Figs. 1245 inclusive.

Referring now to Fig. 16,,to initiate the drying cycle of operation of the dryer, the selector control knob 75 is turned so that its pointer 750 points to the Dry position on the selector control dial 76. If a coin controlled switch 74 is employed, a proper coin is inserted therein and the operating lever 740 thereof is turned to A back to B and is released. This closes the contacts 741 and 742 and the contacts 743 and 744 of the said coin controlled switct '74 which remains closedluntil the drying cycie of operation is completed and the selector control knob 75 is turned from its Dry position to either its Off or Night position, the Night position initiating the reactivation cycle of operation or the hair dryer as hereinatter described.

The turning of the selectorknob .75 to its Dry position from its Ofi position turns the selector control rod 77 counterclockwise whereupon the relay ca m-8300 thereon moves counterclockwise but not sufficiently to operate the relay 83. The micro-switch cam 8200' which also turns counterclockwise when the selector knob 75is turned from its Oil to its Dry position, turns sufficiently to open the micro-switch contacts 820 and 821 and. close the microswitch contacts 32% and 822. Electric current now is available to the electric motor 62 of the .b'LOWSI 27, and the hair drying cycle of operation begins. The remaining controls, both electrical and mechanical, are not changed from their original positions as described when the selector control knob 75; is .in its Off position. Electric current is available to the c01n'fortl1'eater64 and the reading lamp 67 through the comfort heater sw-itch and the reading lamp switch 66.

The turning of the selector knob to its Dry position does not turn the selector control,leverfl78' at the' bottom of the selector control rod 77 sufficiently to cause the selector control lever to engage the portions 790 and 791 of the rod type earn 79 depending from the hinged bafiie 73 in the blower discharge duct 41, consequently; the

said hinged baffie 73 remains inits closed position sealing off the humid reactivation air discharge outlet 71;in the said blower discharge duct 41. See figs. 17 and 18.

The turning of the selector knob 75 from its Dry position to either its 01f or Nightposition opens the microswitch contacts 82!} and 822 and closes the rhicroeswitch contacts ass and i821. Th shiitsotfc itrrent to the contaZ-ct's 741 and 742 and the contacts 743 and 744 coin controlled switch 741whic e ly cludesja timing mechanism, not shown; which opens contacts 743 7 and 744 upon the expiration of a predetermined time, which contacts 743 and 744 remain open until another coin is placed therein and the operating lever 740 thereof manipulated, thus preventing further operation of the dryer on its drying cycle of operation until another coin is placed in the coin controlled switch 74 even though the selector knob 75 is again turned to its Dry position. During the time the contacts 743 and 744 remain closed under control of the timing mechanism of the coin controlled switch 74, the drying cycle of operation may be turned on and off at will by the turning of the selector knob 75 from Dry to Off and vice versa. However, if a coin controlled switch 74 is not employed, the turning of the selector knob 75 again to its Dry position will reinitiate the drying cycle of operation of the hair dryer.

Fig. 19 repeats, in part, that portion of the wiring diagram and electrical controls shown in Fig. 9 as are affected by the operation of the selector control knob '75; the electromechanical controls being shown in the Dry or drying cycle of operation position in Figs. 1619 inclus1ve.

Referring now to Fig. 20, to initiate the reactivation cycle of operation of the hair dryer, the selector control knob 75 is turned so that its pointer 750 points to the Night position on the selector control dial 76. The re activation cycle position on the dial 76 is marked Night because, in most cases, reactivation of the hair dryer will be accomplished after a normal days use, and generally after a beauty salon has been closed.

The turning of the selector knob 75 to its Night position from its Dry position turns the selector control rod 77 counterclockwise, moves the relay cam 8300 thereon counterclockwise and deflects a leaf spring 86 which contacts a tongue 87 on the relay 83 and closes the normally spring loaded open contacts 830 and 831 of the said relay 83. This actuates the coil 835 of relay 83 which holds closed contacts 830 and 831 thereof, breaks the spring loaded closed contacts 832 and 833 thereof, and closes and holds closed contacts 832 and 834 thereof. Current is now supplied to the motor 62 of the blower 27 and the reactivation heater 32. No current can pass to the comfort heater 30 and the reading lamp 67. It will be noted that, as soon as the selector knob 75 is released after its having been turned manually counterclockwise sufliciently to close the normally spring loaded open contacts 830 and 831 of the relay 83, the leaf spring 86 moves the relay cam 8300 slightly clockwise as indicated by the dot and dash lines 861 and 8301 in "Fig. 20. This permits the spring 836 of the relay 83 to open the contacts 832 and 834 of the relay '83 and hold open contacts 830 and 831 of the said relay 83 as soon as the reactivation cycle thermostatic shut-off switch 84 preferably located in the blower discharge duct 41 ahead of the hinged haflle 73 opens responsive to hot air passing thereover. Once the reactivation cycle thermostatic shut-off switch 84 is opened, all of the elements of the electric circuit are in their Off position and no more current passes to the electric motor 62 of the blower 27 and the reactivation heater 32. When the reactivation cycle thermostatic shut-off switch 84 closes due to cooling thereof after 'the completion of a reactivation cycle of operation, the hair dryer is again ready for use in its drying cycle of operation by turning the selector knob 75 to Dry.

When the reactivation cycle of operation of the hair dryer is initiated by turning the selector knob 75 to its Night position, the selector control lever 78 at the bottom of the selector control rod 77 is turned sufficiently to cause the said selector control lever 78 to engage the portion 791 of the rod type cam 79 and pivot the hinged baffle 73 in the blower discharge duct 41 upwardly whereupon the humid reactivation air discharge outlet 71 in the blower discharge duct 41 is opened and the hafile 73 blocks the blower discharge duct 41 beyond the humid reactivation air discharge outlet 71 causing humid reactivation air to discharge .theret-hrough; see Figs. 21 and 22.

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When the selector knob 75 is turned from Night to Dry or off, the selector control lever 78 on the selector control rod 77 is turned out of engagement with the portion 791 of the rod type cam 79 and engages the portion 790 of the said rod type cam 79 sufficiently to pivot the hinged baffle 73 from its open position shown in Figs. 11, 21 and 22 to its closed position shown in Figs. 5, 6, 8, 13, 14, 17 and 18 where it remains by gravity until the selector knob 75 is again turned to Night.

Fig. 23 repeats, in part, that portion of the wiring and electrical controls shown in Fig. 9 as are affected by the operation of the selector control knob 75; the electromechanical controls being shown in the Night or reactivation cycle of operation position in Figs. -23 inelusive.

When a hair dryer embodying the invention is placed in use, the annular desiccant basket 29 is filled with a desiccant 28 such as silica gel which readily adsorbs moisture on the surface of the granules thereof and readily releases the said moisture to ambient air at an elevated temperature passing over the moisture laden surface of the said granules. The power plug 81 is connected to a suitable source S of alternating current. The selector knob 75 is turned to its Off position. The helmet 26 is placed over the head of a user with the users head disposed within the head cavity 260 of the said helmet 26. The selector control knob 75 is turned to Dry initiating the drying cycle of operation of the hair dryer.

During the drying cycle of operation of the hair dryer the blower 27 supplies dehumidified air drawn from the desiccant basket 29 to the head cavity .260 of the helmet '26, draws moisture laden air from the head cavity 260 of the helmet 26 Where the dehumidified air circulated thereto has picked up moisture from the users hair through the desiccant basket 29. If the dehumidified air supplied to the helmet 26 is uncomfortably cool to the user of the hair dryer, the comfort heater 30 is turned on whereby the substantially dry air supplied to the helmet 26 is warmed. When dehumidified air supplied to the helmet 26 becomes sufficiently heated for comfort, the comfort heater is turned off. If the dehumidified air supplied to the helmet 26 should become uncomfortably warm, then the ambient air bleed 31 is employed by open ing the ambient air bleed slid-ing door 68 sufficiently to permit a suitable amount of ambient air to bleed through the ambient air passage 69 into the dehumidified air stream within the hair dryer whereby to cool the dehumid-ified air supplied to the helmet 26 to a comfortable temperature. The opening of the ambient air bleed sliding door 68 opens the contacts 850 and 851 of the safety ambient air bleed interlock micro-switch 85. When the drying cycle of operation is completed, the selector con trol knob is turned to Off. This drying cycle of operation can be repeated as often as desired within the limits of the adsorptive capacity of the desiccant 28, either with or without employing the comfort heater 30 or the ambient air bleed 31.

After a full days operation of the hair dryer or when the desiccant 28 has adsorbed substantially its capacity of moisture from air circulated therethrough during the drying cycle of operation, then the hair dryer must be reactivated. This is accomplished by turning the selector knob 75 to its Night position whereupon the reactivation cycle of operation of the hair dryer is initiated.

If the ambient air bleed sliding door 68 is in a partially or fully open position when the reactivation cycle of operation is initiated by turning the selector knob 75 to Night, the reactivation cycle will not start because the contacts 850 and 851 of the safety ambient air bleed interlock micro-switch is open. To start the reactivation cycle, the ambient air bleed sliding door must be closed which closes the contacts 850 and 851 of the safety ambient air bleed interlock micro-switch 85. The reason for the ambient air bleed safety interlock is that the duration of the reactivation cycle of operation of the dryer is controlled by the reactivation cycle thermostatic shut-otf switch 84 which breaks the reactivation cycle electric circuit responsive to the tem -erature of reactivation air passing through the blower discharge duct 41.

When the reactivation cycle of operation of the hair dryer is initiated, the desiccant 28 has had adsorbed on the granules thereof considerable moisture. Ambient air heated by the reactivation heater 32 is drawn through the desiccant whereupon the said heated ambient air picks up the moisture adsorbed on the granules of the desiccant 28 during the drying cycle of operation of the dryer and is drawn through the blower 27 and discharged therefrom through the blower discharge duct 41 as humid reactivation air. This humid reactivation air becomes less humid as the moisture remaining on the crystals of the desiccant 28 is reduced until, when the desiccant is completely reactivated, the humid reactivation air becomes substantially dry and the temperature thereof rises. When the temperature of the substantially dry humid reactivation air rises sufficiently to open the reactivation cycle thermostatic shut-oif switch 84, the reactivation cycle of operation is completed. If ambient airwerepermitted to enter the hair dryer through the ambient air bleed sliding door 68 and ambient air bleed passage 69 into the path of the humid reactivation air being drawn into the blower 27 during the drying cycle of operation, the humid reactivation air would never become warm enough to open the reactivation cycle thermostatic shut-off switch 84 because of the cooling of the reactivation cycle thermostatic shutoff switch 84 by ambient air mixed therewith.

Once the reactivation cycle of operation of the hair dryer has been initiated, it may be stopped manually at any time by turning the selector control knob 75 from Night to Off or Dry. However, after the reactivation cycle of operation is completed and shut off automatically by the reactivation cycle thermostatic shut-off switch 84, the reactivation cycle of operation cannot be reinitiated until the reactivation cycle thermostatic shut-E switch 84- has cooled sufficiently to permit its contacts 840 and 841 to re-make.

The particular illustrative embodiment of the invention preferably employs a /s horsepower electric motor 62 to drive the impeller 270 of the blower 27 which is proportioned to provide a very low velocity of dehumidified air in the helmet 26; for example, 60 to 75 C. F. M. being the preferable velocity of air movement during the drying cycle of operation which avoids any feelingof disturbance of the hair when being dried by the hair dryer. A 500 watt comfort heater 30 and a 1500 watt reactivation heater 32 is generally sufficient. The reactivation cycle thermostatic shut-01f switch 84 preferably operates at 180 to 200 degrees Fahrenheit, at which temperature the hair dryer and the desiccant 28 does not become unduly overheated during the reactivation cycle of operation. Although the foregoing suggested design factors have been found to be desirable and preferable, they are presented herein for the purpose of illustration and not limitation.

Of importance in the invention herein disclosed is the fact that, because of the particular recirculation system employed during the drying cycle of operation wherein moisture laden air from the helmet is circulated through the desiccant and returned to the helmet as dehumidified air having a moisture content of from /2.% to 5%, the moisture content of the moisture laden air leaving the helmet during the drying cycle of operation While drying a head of hair therein rangesusually from to This is distinguished from moisture contentn'in hair dryers which draw ambient air into the dryer and through the desiccant wherein the humidity of, air passing throughathe desiccant averages from 40% to 80% depending upon the humidity of the ambient air drawn into the helmet. Thus, the amount of moisture in airn passing through the desiccant and the heat of adsorption of the desiccant in hair dryers embodyingthis invention is .muchless than in others, thereby making hair dryers embodying this inven- Hi tion more efiicient and comfortable because of the relatively low temperature and humidity of air circulating through the helmet.

In addition, the recirculation system employed which only needs remove actual moisture picked up from the head of hair being dried results in the desiccant adsorbing less moisture and remaining cooler and more eflicient than in conventional hair dryers, all of which in turn makes for economical and efiicient reactivation cycle operation in that the length of time and power required to reactivate the desiccant is held to a minimum.

The improved and highly efficient and efiective hair dryer herein disclosed drys hair rapidly and comfortably with a low velocity recirculating air system under a novel combination of manual and automatic electrical and thermal controls, and provides an extremely safe and economical hair drying unit for beauty salons and the like.

Although but a single embodiment of the invention has been described in detail, it is obvious that many changes in the size, shape, arrangement and organization of the elements of the invention may be made without departing from the spirit and scope thereof as defined by the appended claims.

I claim:

1. In a re-circulating air hair dryer of the class described, in combination, a desiccant air dehumidifying element and a helmet having a cavity therein to receive a head of hair to be dried, air circulating means comprising a blower having its intake connected to the outlet of said dehumidifying element, drawing moisture laden air from the helmet through the said dehumidifying element and returning dehumidified air to the helmet, a manually adjustable ambient air bleed located in the region of said intake'of said blower to bleed a desired amount of ambient air into dehumidified air at a point where said ambient air is blown to said helmet without first passing through said desiccant, a manually controlled heating element located to heat to comfortable temperature dehumidified air as it is returned to the helmet, and means for reactivating the desiccant air dehumidifying element comprising a manually operated baffle arranged to bypass air returning from the dehumidifying element to the helmet to ambient air whereby to cause ambient air to be drawn into and from the helmet through the dehumidifying element and reactivate the desiccant therein, a reactivation cycle heating element disposed in the path of ambient air from the helmet to the desiccant dehumidifying element, means effective only when the manually adjustable ambient air bleed is open interrupting the operation of the blower and the reactivation cycle heating element, and thermostatic switch means disposed in the path of air from the desiccant air dehumidifying element to ambient air shutting off the blower and the reactivation heater element at a predetermined temperature to which air from the desiccant air dehumidifying element attains when the desiccant therein becomes reactivated.

2. In a hair dryer of the class described having a hair ing ducts from the helmet to the dehumidifying element and from the dehumidifying element to the helmet, air circulating means comprisinga biower drawing moisture laden air from the helmet through the said dehumidifying element and returning dehumidified air to the helmet during the hair drying cycle of operation, a manually adjustable ambient air bleed located to bleed a desired amount of ambient air into dehumidified air as it is returned to the helmet during the hair drying cycle of operation whereby to cool the same, and a manually controlled heating element located to heat to comfort able temperature dehumidified air as it is returned to the helmet during the hair drying cycle of operation, and means for reactivating the desiccant air dehumidifying element during the reactivation cycle of operation comprising a manually operated baflle arranged to bypass air returning from the dehumidifying element to the helmet to the ambient air whereby to cause ambient air to be drawn into and from the helmet through the dehumidifying element and reactivate the desiccant therein, a reactivation cycle heating element disposed in the path of ambient air from the helmet to the desiccant dehumidifying element elevating the temperature of ambient air passing through the desiccant during the reactivation cycle of operation, means eifective only when the manually adjustable ambient air bleed is open interrupting the operation of the blower and the reactivation cycle heating element, and thermostatic switch means disposed in the path of air from the desiccant air dehumidifying element to ambient air shutting off the blower and the reactivation heater element at a predetermined tempera ture to which air from the desiccant air dehumidifying element attains when the desiccant therein becomes reactivated whereby to shut off the reactivation cycle of operation.

3. In a hair dryer of the class described having a hair drying and reactivation cycle of operation, a manual control turnable to shut the hair dryer off or to initiating the drying cycle or reactivation cycle of operation thereof, a desiccant air dehumidifying element and a helmet having a cavity therein to receive a head of hair to be dried, air circulating ducts from the helmet to the dehumidifying element and from the dehumidifying element to the helmet, air circulating means comprising a motor driven blower actuated when the said manual control is turned to the drying cycle of operation drawing moisture laden air from the helmet through the said dehumidifying element and returning dehumidified air to the helmet during the hair drying cycle of operation, a manually adjustable ambient air bleed located to bleed a desired amount of ambient air into dehumidified air as it is returned to the helmet during the hair drying cycle of operation whereby to cool the same, and a manually controlled heating element located to heat to comfortable temperature dehumidified air as it is returned to the helmet operable only during the hair drying cycle of operation, and means including the said motor driven blower for reactivating the desiccant air dehumidifying element during the reactivation cycle of operation actuated when the said manual control is turned to the drying cycle of operation comprising a manually operated bafile arranged to by-pass air returning from the dehumidit'ying element to the helmet to ambient air whereby to cause ambient air to be drawn into and from the helmet through the dehumidifying element and reactivate the desiccant therein, a reactivation cycle heating element actuated responsive to the said turning of the manual control to the drying cycle of operation disposed in the path of ambient air from the helmet to the desiccant dehumidifying element elevating the temperature of ambient air passing through the desiccant during the reactivation cycle of operation, means effective only when the manually adjustable ambient air bleed is open preventing the operation of the blower and the reactivation cycle heating element, and thermostatic switch means disposed in the path of air from the desiccant air dehumidifying element to ambient air shutting off the blower and the reactivation heater element at a predetermined temperature to which air from the desiccant air dehumidifying element attains when the desiccant therein becomes reactivated whereby to shut ofi the reactivation cycle of operation.

4. A hair dryer comprising a helmet, a housing forming a moisture laden air chamber, means forming a de humidified air chamber within said moisture laden air chamber, a desiccant basket including desiccant therein disposed in the said dehumidified air chamber in communication with the said moisture laden air chamber through which moisture laden air passes and becomes dehumidified as it enters the said dehumidified air chamber, the said helmet being composed of an inner shell and an outer shell forming a dehumidified air distribution chamber therebetween, the helmet inner shell having dispersed dehumidified air nozzle apertures therein and a mositure laden air return port therethrough, a moisture laden air conduit through which moisture laden air is conducted from the helmet moisture laden air return port to the moisture laden air chamber, a dehumidified air conduit through which dehumidified air is conducted from the dehumidified air chamber to the dehumidified air distribution chamber in said helmet, a motor driven blower having a blower intake communicating with the said dehumidified air chamber and a discharge port communicating with the said dehumidified air conduit which draws moisture laden air from the said helmet through the said desiccant basket and supplies dehumidified air to the said helmet during the hair drying cycle of operation of the dryer, an ambient air bleed passage communicating with the said dehumidified air chamber, means for regulating the amount of ambient air bleed into the dehumidified air passing through the said dehumidified air chamber, a comfort heater element disposed in the dehumidified air conduit between the dehumidified air chamber and the dehumidified air distribution chamber in the said helmet, and means for controlling the comfort heater by the user of the hair dryer, a manually operable bathe in the said dehumidified air conduit arranged to by-pass air from the dehumidified air chamber to the ambient air during the reactivation cycle of operation of the dryer whereby to cause ambient air to be drawn from the helmet to and through the desiccant in the desiccant basket during the said reactivation cycle of operation of the dryer and reactivate the said desiccant, a reactivation cycle heating element disposed in the path of ambient air from the helmet to the desiccant dehumidifying element elevating the temperature of ambient air passing through the desiccant during the reactivation cycle of operation, means etfective only when the manually adjustable ambient air bleed is open interrupting the operation of the blower and the reactivation cycle heating element, and thermostatic switch means disposed in the path of air from the desiccant air dehumidifying element to ambient air shutting oi? the blower and the reactivation heater element at a predetermined temperature to which air from the desiccant air dehumidifying element attains when the desiccant therein becomes reactivated whereby to shut off the reactivation cycle of operation.

5. In a hair dryer of the class described, in combination, a desiccant air dehumidifying element and a helmet having a cavity therein to receive a head of hair to be dried, air circulating means comprising a duct system and an electric motor driven blower drawing moisture laden air from the helmet through the said dehumidifying element and returning dehumidified air to the helmet, the said helmet having therein a plurality of apertures for dispersing dehumidified air supplied thereto throughout the helmet head cavity and a port through which dehumidified air supplied to the helmet leaves the helmet as moisture laden air, a manually adjustable ambient air bleed located in the duct system through which a desired amount of ambient air may be bled into dehumidified air as it is returned to the helmet whereby to cool the same and a manually controlled electric heating element located in the duct system whereby at the option of the user to heat to comfortable temperatures dehumidified air as it is returned from the dehumidifying element to the helmet, the said duct system having a bypass port to ambient air therein, means for reactivating the desiccant air dehumidifying element comprising a manually operated baffle located in the duct system arranged to by-pass air normally returning from the dehumidifying element to the helmet through the said bypass port to ambient air whereby to cause ambient air to be drawn from the helmet through the dehumidifying element and reactivate the desiccant therein, and an electric reactivation cycle heating element disposed in the duct system in the path of ambient air from the helmet to the desiccant dehumidifying element, and manualelectric control means adapted to initiate and shut off the drying cycle of operation and the reactivation cycle of operation including cam means operated responsive to the initiation of the reactivation cycle of operation moving the said bafiie whereby to close the said by-pass port to ambient air during the drying cycle of operation and operated responsive to the initiation of the drying cycle of operation moving the said bathe whereby to open the said by-pass port to ambient air during the reactivation cycle of operation.

6. A hair dryer as set forth in claim which includes thermostatic switch means disposed in the duct system in the path of air from the desiccant air dehumidifying element to ambient air shutting off the blower and the reactivation heater element at a predetermined temperature to which air from the desiccant dehumidifying element attains when the desiccant therein becomes reactivated.

7. A hair dryer as set forth in claim 5 which includes thermostatic switch means disposed in the duct system in the path of air from the desiccant air dehumidifying element to ambient air shutting off the blower and the reactivation heater element at a predetermined temperature to which air from the desiccant dehumidifying element attains when the desiccant therein becomes reactivated, and means operated by the manually adjustable ambient air bleed preventing the initiation of the reactivation cycle of operation when the ambient air bleed is open.

8. A hair dryer comprising a helmet, means forming a chamber having desiccant therein, an air blower, conduit means connecting said helmet, said chamber, and said blower in series relationship in the order stated so as to form a closed recirculating air path, whereby air is sucked by said blower from said helmet through said chamber to said blower and is blown by said blower back to said helmet, said desiccant in said chamber acting to remove moisture from air passing through same and tend ing to heat said air because of latent heat of adsorption, means forming an ambient air bleed opening from the outside atmosphere into said recirculating air path at a point near the outlet side of said chamber and the intake side of said blower, to bleed ambient air into said recirculating air path at a point where said ambient air is blown to said helmet without first passing through said desiccant, thereby preventing said ambient air from being heated by said desiccant prior to reaching said helmet, a door movable with respect to said opening for regulating the efiective size thereof, and means for maintaining said door in an open position during the progress of drying operations toadmit ambient air to compensate for the effect of said latent heat of adsorption in heating the recirculated 9. In a hair dryer of the class described, in combination, a desiccant air-dehumidifying element, a helmet having a cavity therein to receive a head of hair to be dried, air circulating means comprising a duct system and a blower drawing moisture laden air from said helmet through said dehumidifying element to said blower and returning dehumidified air from said blower to said helmet, manually adjustable means forming an ambient air bleed opening from the outside atmosphere into said duct system at a point near the outlet side of said dehumidifying element and the intake side of said blower, whereby ambient air is bled through said air bleed opening into said duct system at a point where said ambient air is blown to said helmet without first passing through said desiccant, said adjustable means being adapted to open and close said opening, an electric reactivation cycle heating element disposed in said duct system in the path of air from said helmet to said desiccant dehumidifying element, and means operated by said manually adjustable ambient air bleed means for preventing energization of said electric heating element and initiation of the reactivation cycle of operation, when said ambient air bleed is open.

10. In a hair dryer of the class described, in combination, a desiccant air dehumidifying element, a helmet having a cavity therein to receive a head of hair to be dried, air circulating means comprising a duct system and a blower drawing moisture laden air from said helmet through said dehumidifying element to said blower and returning dehumidified air from said blower to said helmet, means forming a manually adjustable ambient air bleed opening located in said duct system at a point on the downstream side of said air dehumidifying element, said duct system having a bypass port to ambient air therein located between said blower and said helmet, downstream of said blower, means for reactivating said desiccant air dehumidifying element comprising a manually operated bafiie located in said duct system and having a reactivating position and a drying position, said baflie when in its reactivating position being adapted to bypass air normally returning from said dehumidifying element to said helmet through said bypass port to ambient air and to prevent it from returning to said helmet, and when in its drying position being adapted to close said bypass port and to direct air returning from said dehumidifying element to said helmet, an electric reactivation cycle heating element disposed in the duct system in the path of ambient air from said helmet to said desiccant dehumidifying element, and manual-electric control means adapted to initiate and shut off the drying cycle of operation and the reactivation cycle of operation, including means for controlling the position of said baflle and for controlling said reactivation cycle heating element and said blower.

References Cited in the file of this patent UNITED STATES PATENTS 1,415,010 Benjamin May 9, 1922 2,066,847 McShea Jan. 5, 1937 2,314,101 Phipps Mar. 16, 1943 2,444,481 Watkins July 6, 1948 2,479,388 Matthews et a1 Aug. 16, 1949 

